2. VIRTUAL PRIVATE NETWORK
Definition
and introductory notes
VPN is the network which uses open
distributed infrastructure of the internet
to transmit data between corporate sites.
3. NEED FOR DEVELOPING VPN
Remote employees interested to access
database of corporations.
Corporate sites developing new relations.
Increasing growth of the corporation.
4. VPN RESOLVES THE
PROBLEM
Itprovides flexibility and scalability
Cost advantage.
Makes free from maintenance and training.
6. WORKING-STEP1 (cont…)
The remote user dials into their local ISP and logs
into the ISP’s network as usual.
BACK
7. WORKING-STEP2 (cont…)
When connectivity to the
corporate network is
desired, the user
initiates a tunnel request
to the destination
Security server
BACK
8. WORKING-STEP3 (cont…)
The user then sends
data through the
tunnel which encrypted
by the VPN software
before being sent over
the ISP connection
BACK
11. Virtual Private Network
VIRTUAL LEASED LINES
Point to point link
between two CPE
IP tunnel between
2 ISP edge
routers.
Frames are relayed
between IP tunnels.
12. Virtual Private Network
VIRTUAL PRIVATE ROUTED
NETWORK
Emulation of multisite
WAN using internet.
Packet forwarding at
network layer.
VPRN specific
forwarding table at
ISP routers that
forwards the traffic.
13. VIRTUAL PRIVATE DIAL-UP
NETWORK
On demand tunnel between remote user and
corporate sites.
There are possible 2 tunnels.
1… compulsory tunnel.
2… voluntary tunnel.
14. Virtual Private Network
COMPULSORY TUNNEL
In this scenario L2TP
Access Contractor (LAC)
acting as a dial or
network access server
extends a PPP session
across a backbone using
L2TP to a remote L2TP
Network Server (LNS).
The operation of
initiating the PPP session
to the LAC is transparent
to the user.
BACK
15. Virtual Private Network
VOLUNTARY TUNNEL
Voluntary tunnel refers
to the case where an
individual host connects
to a remote site using a
tunnel originating on the
host, with no involvement
from intermediate
network nodes. Tunnel
mechanism chosen can be
IPSec or L2TP.
16. VIRTUAL PRIVATE LAN
SEGMENTS
A Virtual Private
LAN Segment
(VPLS) is the
emulation of a LAN
segment using
internet facilities.
17. INTRANET VPN
The branch office
scenario securely
connects two trusted
intranets within the
organization.
Routers or firewalls
acting as gateways for
the office with vpn
capabilities can be
used to protect the
corporate traffic.
18. EXTRANET VPN
Inthis scenario multiple supplier intranets that need
to access a common corporate network over the
Internet. Each supplier is allowed access to only a
limited set of destinations within the corporate
network.
19. REMOTE ACCESS VPN
A remote user wants to be able to communicate securely
and cost-effectively to his corporate intranet. This can
be done by use of an VPN IPSec enabled remote client
and firewall (or gateway).
22. POINT TO POINT
TUNNELING PROTOCOL
Introduction to PPTP.
How actually PPTP works ???
Security provided by PPTP.
Advantages of PPTP.
Disadvantages of PPTP.
BACK
25. CERTAIN H/W AND S/W
SPECIFICATIONS…
Desktop software client for each remote
user
Dedicated hardware such as a VPN
Concentrator or Secure
PIX Firewall
Dedicated VPN server for dial-up services
NAS (Network Access Server) used by
service provider for
remote user VPN access
26. Virtual Private Network
VPN CONCENTRATOR
Itincorporates the
most advanced
encryption and
authentication
techniques for
Remote access
VPN.
30. ADVANTAGES OF VPN
Cost saving.
Reduces the long distance charges of
electronic transactions.
Concrete security.
31. DISADVANTAGES OF VPN
VPNs require an in-depth understanding of public network security
issues and taking proper precautions in VPN deployment.
The availability and performance of an organization's wide-area
VPN (over the Internet in particular) depends on factors largely
outside of their control.
VPN technologies from different vendors may not work well
together due to immature standards.
32. CONCLUSION
From this we can conclude that VPN
provides a very safe , secure and cost-
effective communication infrastructure.